Crazy Horse was the most famous and perhaps greatest of the Sioux commanders, and led his warriors to victory in four major confrontations with the US Army, including the famous Battle of Little Big Horn. He was born in the winter of 1841-42, and his father, also called Crazy Horse, was a revered holy man. According to legend, he was a solitary but curious child, but at about 12 years of age, he was in a Lakota (Sioux) encampment as a famous moment in frontier history unfolded, on 19 August 1854.

A cow had wandered off from a passing Mormon caravan, and been killed for meat and leather by a visitor to the Sioux encampment. US troops led by Lt John Grattan (1830-1854) arrived and demanded that the visitor be remanded into their custody, and the band's elder, Conquering Bear (c. 1800-1854), offered apologies and restitution, but refused to let the Whites take his visitor. At some point during a tense standoff, a jittery soldier drew his gun and shot a native, and suddenly gunshots and arrows filled the air. Conquering Bear was shot and killed, the only Sioux casualty in what became known as the Grattan massacre — Lt Grattan and 29 of his soldiers were killed.

Witnessing this, the boy was deeply troubled, and rode alone to the peak of a tall hill, where he laid on the ground, pondered it all, and — after three days of fasting — had a powerful vision. He saw a warrior riding his horse through furious battle and thunderstorm without injury, untouched by arrows and bullets, and knew that the warrior, who had a lightning bolt on his cheek, was invulnerable. For the remainder of his life, Crazy Horse painted a lightning bolt on his cheek before battle. He was not invulnerable, of course, but in his many battles Crazy Horse was never more than slightly wounded.

On 3 September 1855, while he was still a boy, he witnessed the US Army's retaliation for the Grattan massacre, the Battle of Ash Hollow, as Gen William Harney (1800-1889) led an attack that left more than a hundred Sioux dead. Crazy Horse was not injured, but he was left with a life-long hatred of the Whites. Over the next decade he grew into a respected warrior, for his leadership in several battles that effectively blocked US plans to open the Bozeman Trail to settlers and gold miners in Sioux territory.

On 21 December 1866, he led Sioux forces in the Fetterman massacre, killing Captain William J. Fetterman (1833-66) and his men after luring them into an intricately laid trap near an Army fort. Two years later, Chief Red Cloud (1822-1909) signed a treaty with the Americans, agreeing to relocate the tribe to a reservation on the west side of the Missouri River, but Crazy Horse and his followers refused to resettle. In 1873 and '74 warriors led by Crazy Horse repeatedly engaged troops commanded by General George Armstrong Custer.

At about this time, Crazy Horse fell in love with Black Buffalo Woman, who eventually married another man, No Water. Crazy Horse and No Water feuded after her marriage, and at one point their rivalry came to a gunfight, leaving Crazy Horse wounded. He later married an Oglala woman, Black Shawl, but in 1876 his quiet domestic life was shattered, when a peaceful encampment of Sioux was attacked by Army troops under the command of General Joseph J. Reynolds (1822-1899), and the survivors from this battle sought refuge with Crazy Horse. He swore that he would avenge the dead, and attacked the bluecoats in the Battle of Rosebud Creek on 17 June 1876, a decisive victory for the Sioux.

A week later, on 25 June 1876, Custer's men attacked Crazy Horse's forces, which by then included several thousand native warriors. The Battle of Little Bighorn was fatal for Custer and some 250 of his men, but in response the US flooded the Plains with so many well-armed soldiers that the Sioux could not possibly win. As Union forces advanced over subsequent months, Crazy Horse's militia split in two, with some retreating to Canada while others, under Crazy Horse, fought on.

In December of 1876, cold, hungry, and almost out of ammunition, he sent a small party of men bearing white flags, seeking terms of surrender from General Nelson A. Miles, but Miles' men opened fire on the surrender party. With his warriors and thousands of women and children, Crazy Horse then fled with Miles' men in pursuit, and on 8 January 1877, exhausted, outnumbered, and low on ammunition, the Army attacked while Crazy Horse and his men slept. Though the Sioux soon ran out of bullets and were reduced to fighting with bows and arrows, it was the Whites who eventually withdrew from the Battle of Wolf Mountain.

That spring, Army emissaries sent Crazy Horse promise of a reservation alongside the Powder River if he would surrender, and at the urging of the respected Chief Red Cloud, Crazy Horse and his men laid down their arms on 5 May 1877. The reservation they were promised was never granted, but Crazy Horse camped on Red Cloud's reservation for a few months. In the pre-dawn hours of 5 September 1877, he was roused from his sleep by order of General George Crook (1828-1890), and told he would be meeting with an Army officer. Instead Crazy Horse was taken to a guardhouse, and when he understood that he was about to be imprisoned he attempted to escape, and was fatally bayoneted in the back. His body was turned over to his parents, who had him buried but never revealed the whereabouts of his grave.